10,389 research outputs found
Self-organized mapping of calorimetry information for high efficient online electron/jet identification in ATLAS
Study of psi' and chi_c decays as feed-down sources of J/psi hadro-production
The interpretation of the J/psi suppression patterns observed in nuclear
collisions, at CERN and RHIC, as a signature of the formation of a deconfined
phase of QCD matter, requires knowing which fractions of the measured J/psi
yields, in pp collisions, are due to decays of heavier charmonium states. From
a detailed analysis of the available mid-rapidity charmonium hadro-production
cross sections, or their ratios, we determine that the J/psi feed-down
contributions from psi' and chi_c decays are, respectively, (8.1 +/- 0.3) % and
(25 +/- 5) %. These proton-proton values are derived from global averages of
the proton-nucleus measurements, assuming that the charmonium states are
exponentially absorbed with the length of matter they traverse in the nuclear
targets.Comment: 12 pages, 4 figures, 3 table
Absorption and J/psi Suppression in Heavy Ion Collisions
We discuss the J/psi suppression in the framework of multiple collision
models. From the analysis of the Pb-Pb NA50 data we conclude that the strength
of the absorption has increased, but we find no clear evidence for the
formation of the quark-gluon plasma.Comment: 8 pages, 4 figure
A Whole-Institution Approach Towards Sustainability at NOVA University: A Tangled Web of Engagement Schemes
Abstract. NOVA University Lisbon ambition to become a sustainable university following a whole-institution approach raises several challenges, due to the diversity of culture and governance of its nine schools spread over eight campuses in four municipalities. Engaging NOVA community is critical to achieve systemic changes, but very hard to carry coherently and at the same pace across all schools and throughout all its members. Different engagement schemes, interlinking a top-down one from the rector and the board of deans, who leads the vision, with several bottom-up schemes in education, research, value creation and operations are being implemented to carry out different purposes towards the common goal. NOVA for the Globe strategic platform and NOVA zero-waste task force are examples, among others, showing sustainability implementation at the university starts with people cooperation around the same ambition.Keyword: Strategic Thinking, Systemic Change, Engagement, University, Whole-Institution Approach
From âcreative citiesâ to âurban creativityâ? Space, creativity and governance in the contemporary city
DINĂMIA, Dezembro de 2009This paper derives from a broader research program studying the forms of governance associated with creative dynamics in cities (the âCreatcityâ project) and draws on the first empirical results generated by the
study following analysis of a set of exploratory interviews involving actors central to thinking and acting on
the contemporary city (political decision makers, official structures and civil society) in the three
metropolitan areas selected for the project: Lisbon (Portugal), SĂŁo Paulo (Brazil) and Barcelona (Spain).
Analysis of the responses sought to identify the different perspectives on the concepts of urban creativity and
creative city and the relationship between creativity, vitality and competitivity within urban contexts while seeking to understand interviewee perspectives on the structural conditions necessary for the development of
creativity in the city in terms of spatial/geographic configurations and the associated cultural ambiances and
economic activities. In parallel, we aim to debate the means of fostering and supporting creativity in urban environments and discuss just which strategic policies and governance processes best achieve this.FC
Synteny-based genome assembly for 16 species of Heliconius butterflies, and an assessment of structural variation across the genus
Heliconius butterflies (Lepidoptera: Nymphalidae) are a group of 48 neotropical species widely studied in evolutionary research. Despite the wealth of genomic data generated in past years, chromosomal level genome assemblies currently exist for only two species, Heliconius melpomene and H. erato, each a representative of one of the two major clades of the genus. Here, we use these reference genomes to improve the contiguity of previously published draft genome assemblies of 16 Heliconius species. Using a reference-assisted scaffolding approach, we place and order the scaffolds of these genomes onto chromosomes, resulting in 95.7-99.9% of their genomes anchored to chromosomes. Genome sizes are somewhat variable among species (270-422âMb) and in one small group of species (H. hecale, H. elevatus and H. pardalinus) expansions in genome size are driven mainly by repetitive sequences that map to four small regions in the H. melpomene reference genome. Genes from these repeat regions show an increase in exon copy number, an absence of internal stop codons, evidence of constraint on non-synonymous changes, and increased expression, all of which suggest that at least some of the extra copies are functional. Finally, we conducted a systematic search for inversions and identified five moderately large inversions fixed between the two major Heliconius clades. We infer that one of these inversions was transferred by introgression between the lineages leading to the erato/sara and burneyi/doris clades. These reference-guided assemblies represent a major improvement in Heliconius genomic resources that enable further genetic and evolutionary discoveries in this genus
Heavy-ion Physics at a Fixed-Target Experiment Using the LHC Proton and Lead Beams (AFTER@LHC): Feasibility Studies for Quarkonium and Drell-Yan Production
We outline the case for heavy-ion-physics studies using the multi-TeV lead
LHC beams in the fixed-target mode. After a brief contextual reminder, we
detail the possible contributions of AFTER@LHC to heavy-ion physics with a
specific emphasis on quarkonia. We then present performance simulations for a
selection of observables. These show that , and
production in heavy-ion collisions can be studied in new energy and
rapidity domains with the LHCb and ALICE detectors. We also discuss the
relevance to analyse the Drell-Yan pair production in asymmetric
nucleus-nucleus collisions to study the factorisation of the nuclear
modification of partonic densities and of further quarkonia to restore their
status of golden probes of the quark-gluon plasma formation.Comment: 18 pages, 7 figure
Feigenbaum networks
We study dynamical systems composed of a set of linearly coupled quadratic maps which, if uncoupled, would be on the Feigenbaum accumulation point. For two units we prove the existence of an infinite number of sinks for an open set of coupling parameters. In the limit of many units a mean field analysis also implies the stabilization in periodic orbits of, at least, a subset of the coupled units. Possible applications in the fields of control of chaos, signal processing through complex dynamics and as models of self-organization, are discussed
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